It looks like I'll either have to pull the whole dash, or run a proper ground wire like you suggested. (mechanics.stackexchange.com)
The colour and trim options deserve a special mention because they're totally unique: grey cotton fabric, embossed leather - like stuff over the whole dash, and carbon - fibre woven with copper are all available. (autofocus.ca)
The whole dash angles towards the driver creating the new cabin concept Toyota calls the «Me Zone.» (carprousa.com)